Use of acidic sodium polyphosphates for the production of cheese

ABSTRACT

The invention concerns the use of acidic sodium polyphosphates and Maddrell&#39;s salt for the production of natural cheese, processed cheese and cheese preparations which have a P 2  O 5  content of 73-77 wt. %, on Na 2  O content of 20-25 wt. %, a water content of 2-3 wt. % and an average linear degree of condensation of 8-20. Preferred are the polyphosphates which are present as comparatively long chains (catena compounds) which are possible cross-linked and contain sodium metaphospbates (tri- and tetra-phosphates) in below 2 wt. %.

FIELD OF THE INVENTION

The subject of the invention is the use of acidic sodium polyphosphatesfor the production of natural cheese, processed cheese and cheesepreparations.

DESCRIPTION OF RELATED ART

Phosphates are already used to a wide extent in the foodstuff industryand also in the cheese industry. In the cheese industry, as processingsalts there are especially used orthophosphates, pyrophosphates andtripolyphosphates and highly condensed polyphosphates with P₂ O₅contents of 60-70 wt. % with sodium, potassium or calcium as cations. Itis known that these compounds possess a certain anti-bacterial action,especially against gram-positive bacteria, and thus can be used aspreserving agents for foodstuffs. An anti-oxidative action for meat andmeat products is also known. Such polyphosphates are also used asprocessed cheese additives and as stabilisers in the production ofcondensed milk.

In the case of the polyphosphates, a differentiation is to be madebetween the chain-shaped ones, systematically designated as catenspolyphosphates, and the ring-shaped cyclopolyphosphates, which arefrequently also referred to as metaphosphates. The production of aseries of defined acidic metaphosphates with P₂ O₅ contents of 75-78 wt.% and Na₂ O contents of 24-17 wt. % and water contents of 2-6 wt. % isdescribed in U.S. Pat. No. 2,774,672, according to which these productscan be used as bakery rising agents. This patent specification alsogives the phase diagram for sodium phosphate/phosphoric acid mixtures independence upon the temperature.

According to the Food Chemical Coder (FCC III), polyphosphates andmetaphosphates are legally permitted for foodstuff purposes when theyhave P₂ O₅ contents of 60-71 wt. %.

SUMMARY OF THE INVENTION

Surprisingly, it has now been ascertained that acidic sodiumpolyphosphates with P₂ O₅ contents of 70.6-77 wt. % and sodium oxidecontents of 20-27 wt % which also have a residual water content of about2-3 wt. % can be used with great success not only as processingadjuvents but also as stabilising agents in the cheese industry.

DETAILED DESCRIPTION

The polyphosphates preferably have a P₂ O₅ content of 71-73 wt. %.Polyphosphates with a P₂ O₅ content of 70.0 or below are practicallyuseless as stabilising agents. Hitherto, it has not been known upon whatthis sudden change of action depends.

For a use of the polyphosphates as processing salt, a content of about2-4 wt. % of the processing is necessary. However, since these compoundsare relatively acidic, it is preferred, in addition to thepolyphosphates, to use other known processing salts, such as trisodiumcitrate or trisodium phosphate, in an amount of 0.5-2 wt. % andcorrespondingly to reduce the content of polyphosphates according to theinvention to 0.1-1 wt. %.

The stabilising and preserving action according to the invention occursat a concentration of 0.1-0.5 wt. % of the cheese mass. Since thephosphates according to the invention, in the case of addition to dairymilk, accumulate on the protein and are precipitated with this, thephosphates according to the invention can also already be added to thedairy milk in an amount of 0.001-0.05 wt. %, preferably of 0.003-0.01wt. %. The nitrates previously added as stabilisers to dairy milk, whichare hazardous to health, can then be dispensed with.

Furthermore, in addition to the polyphosphates, it has proved to beadvantageous also to add a proportion of 0.1-10 wt. parts of Maddrell'ssalt per part of polyphosphate, whereby, in the case of almost equallygood processing salt and stabilising action, the acidity of the mixtureis considerably lowered.

Acidic polyphosphates which are used according to the invention arepreponderantly chain-shaped condensation products with average chainlengths of about 8-20 which are partly also cross-linked but only to asmall extent, i.e. contain an amount of less than 2 wt. % of sodiumtrimetaphosphate and sodium tetrametaphosphate. The above-defined wateris statistically bound chemically in the form of hydroxyl groups to thephosphate chains and has the result that the compounds react relativelystrongly acidically when they are dissolved in water, whereby the 5 wt.% solution displays a pH value of about 1.5-2.5.

The compounds are very hygroscopic and must, therefore, be stored withthe exclusion of moisture in order that they do not clump together. Likeall polyphosphates, they undergo a slow hydrolysis in aqueous solution.Chromatographic analysis shows that, in the case of these products, itis not a question of definite compounds but rather of mixtures in which,of low to high molecular condensation products, practically all arepresent. The average degree of polymerisation can thereby be adjusted toa certain extent by the above-described process procedure.

The dissolving behaviour of the substance in water has a maximum at aphosphate content of about 77 wt. % P₂ O₅ and becomes the better thehigher is the water content, that is the content of free hydroxylfunctions, whereby, at the same time, the degree of cross-linking isalso correspondingly small. However, products with increased content offree hydroxyl functions show increasing hygroscopicity and, especiallyat high temperature, attack metallic surfaces, which can give problemsin the case of grinding and working up.

The content of water or of free hydroxyl functions is expedientlydetermined by determination of the heating loss with the addition ofcalcined ZnO.

The polyphosphates cross-linked with the further loss of water, which inthe literature are frequently also designated as sodiumultrametaphosphates, dissolve only slowly in water with decrease of thepH value of the solution. Therefore, they are less suitable according tothe invention and should only be present in the phosphates in minoramount.

The acidic sodium polyphosphates used according to the invention can beprepared according to known methods for the production of processingphosphates under suitable temperature and mixing conditions (cf. U.S.Pat. No. 2,774,672). On a laboratory scale, mixtures of monosodiumphosphate and phosphoric acid are melted in a platinum crucible in amuffle furnace and quenched on a stainless steel surface. On a technicalscale, the products are melt produced in a chamber oven continuously ordiscontinuously from monosodium phosphate with a definite excess of freephosphoric acid or directly from an adjusted suspension of caustic sodasolution and phosphoric acid. The properties and the dissolvingbehaviour of the products can be controlled by the adjustment of theratio of the caustic soda solution to the phosphoric acid, of theresidence and of the melt temperatures. From the phase diagram in U.S.Pat. No. 2,774,672, which is attached as FIG. 1, it can be seen that,for the products according to the invention with 20-27 wt. % Na₂ O,70-77 wt. % P₂ O₅ and 2-3 wt. % of water, reaction temperatures of above400° C. are necessary. A temperature of 400°-500° C. is preferred.Depending upon the batch size and the continuous or discontinuousprocess procedure, residence times of 20 minutes to about 2 hours,preferably about one hour, are necessary in order to carry out thecondensation to the desired extent and to evaporate off the waterthereby resulting. Subsequent to the melting, the whole mixture ispoured on to cooled metal surfaces, for example appropriate stainlesssteel rollers with internal water cooling, whereby the materialsolidifies to a colourless, translucent phosphate glass which is firstcoarsely broken up and then finely ground in appropriate mills. Thematerial is hygroscopic so that, during the whole of the working upprocess, atmospheric moisture must be excluded. Tightly closedcontainers are also to be used for the storage since otherwise theproduct hardens completely.

In the following Examples, the production of the polyphosphates and thenovel use thereof is described in more detail without the inventionthereby being limited.

EXAMPLE 1 Acidic Sodium Polyphosphate

100 kg of monosodium phosphate (anhydride) and 36 1 of 83 wt. %phosphoric acid (=60 kg)(Na/P=0.62) are homogenized and filled into adiscontinuous chamber oven preheated to 600° C. One heats the mixturefor about 60 minutes to a melt temperature of 400° C. (bathtemperature). The melt surface still clearly shows bubble formation ofemergent water of condensation. Subsequently, one runs off the clearmelt on to a cold casting ingot mould. Upon cooling, the materialbecomes bubble-free and completely glass-clear transparent. The materialis subsequently removed from the casting ingot mould, broken up, groundand stored in airtight containers.

pH value: 1.7 (5 wt. % solution)

P₂ O₅ content: 77.0 wt. %

Na₂ O content: 20.55

H₂ O: 2.45

EXAMPLE 2 Sodium Polyphosphate

50 wt. % caustic soda solution and 83 wt. % phosphoric acid are passedcontinuously, in the ratio of Na/P=0.73, via two measuring pumps andseparate pipes, into a reaction container. There results a hotsuspension of partly neutralised orthophosphoric acid which issubsequently passed into a directly heated chamber oven. The heating ofthe chamber oven is regulated via the off-gas temperature and ismaintained at 500° C. The suspension passes, with condensation, throughthe chamber oven with an average residence time of about 2 hours. Thecompletely reacted melt phosphate is continuously removed at the end ofthe oven via an overflow channel into a water-cooled cooling drum. Thematerial there solidifies to a glass, is subsequently broken up andground. The filling takes place into airtight barrels, taking care fordry storage.

pH value: 1.9

P₂ O₅ content: 73.0 wt. %

Na₂ O content: 24.2

H₂ O content: 2.8

solubility: 90 minutes (stirred 5 wt. % solution) clearly dissolved

heating loss: 2.0 wt. %

Raw materials used:

1) Thermal phosphoric acid (83 wt. %)

Production by burning of elementary phosphorus and adsorption of theresulting phosphorus pentoxide in phosphoric acid with continuousdilution to a definite density by addition of deionised water.

Product data:

density (25° C.): 1.664 g/ml

P₂ O₅ : 60.1 wt. %

As: <0.5 ppm, typically 0.1 ppm

F: <10 ppm

heavy metals: <20 ppm

copper: <10 ppm

zinc: <3 ppm

H₃ PO₄ : <0.1 wt. %

lead: <1 ppm

2) Caustic soda solution (50 wt. %)

density: 1.52 g/l

content: 50.0 wt. %

Hg: <1 ppm

Al: <10 ppm

iron: <3 ppm

chloride: <10 ppm

potassium: <50 ppm

arsenic: <0.3 ppm

EXAMPLE 3 Production of Slicable Cheese

3000 kg of milk with a protein content of 3.4 wt. % and a fat content of3.1 wt. % are pasteurised at 71°-74° C., cooled to 28°-32° C. and mixedwith about 10 1 of an acidification culture (0.15-0.5 wt. %), 600 gcalcium chloride, 300 ml of rennet extract (1:10,000) and, instead ofthe usual sodium nitrate (600 g), with 150 g of sodium polyphosphateaccording to Example 1. After a coagulation and thickening phase ofabout 1 hour, it is converted into cheese in several steps and whey isdrawn off. After about 2 hours, broken pieces of fresh cheese of aboutmillet seed size are obtained.

The pieces of cheese are filled into round pressing moulds (9-10 kg) andpressed with 6-8 kg/cm² at 17°-18° C. for 4 hours.

The final whole cheeses are salted in a salt bath of 24 wt % NaCl at12°-15° C. for 3-5 days and ripened at 14°-16° C. for 2-3 months.Thereafter, either oil is rubbed into the cheese or the cheese is coatedwith wax and further ripened for 2-3 months at 5°-10° C.

EXAMPLE 4 Production of Spreadable Processed Cheese

Processed cheese 45 wt. % of fat in the dry weight, spreadable

15.0 kg Emmentaler

6.0 kg Chester

2.0 kg Tilsiter

2.5 kg whey powder

3.0 kg butter

2.0 kg premelt goods

0.85 Na polyphosphate (60 wt. % P₂ O₅)

0.14 kg Na polyphosphate according to Example 2 22.6 kg water

The above products are mixed together in a stirrer vessel and, with slowstirring, heated up with the passing through of steam in about 10-20 minto the melt temperature of 90°-92° C. Thereafter, it is homogenised withvigorous stirring, the mass poured into moulds, cooled to roomtemperature and temporarily stored for 12 hours. The final storage up touse takes place at 6° C.

There is obtained a spreadable processed cheese which contains 46 wt. %of fat in the dry weight in case of a total dry weight of 46 wt. %.Appearance and consistency do not change even after a storage period of4-6 months.

EXAMPLE 5 Product of Processed Cheese from Fresh Cheese (70 wt. % of fatin the dry weight)

30.0 kg fresh cheese (according to Example 3)

0.45 kg processing salt (trisodium citrate/sodium polyphosphate--60 wt.% P₂ O₅)

0.1 kg citric acid

0.1 kg sodium polyphosphate according to Example 2

1.0 kg Na caseinate

2.0 kg butter

2.0 kg water

are heated in 10 min to about 90° C. by passing through of steam andfurther worked up according to Example 4. In spite of the smallprocessing salt content, a satisfactory processed cheese is obtainedwhich is unchanged even after a storage period of 6 months.

EXAMPLE 6 Production of Slicable Cheese

3000 kg of milk with a protein content of 3.4 wt. % and a fat content of3.1 wt. % are pasteurised at 71°-74° C., cooled to 28°-32° C. and mixedwith about 10 1 of an acidification culture (0.15-0.5 wt. %), 600 g ofcalcium chloride, 300 ml of rennet extract (1:10,000) and, instead ofthe usual sodium nitrate (600 g), with 150 g of a mixture of 90%Maddrell and 10% P71 according to Example 1.

After a coagulation and thickening time of about 1 hour, it is convertedinto cheese in several steps and the whey drawn off. After about 2hours, there are obtained pieces of fresh cheese of approximately milletseed size.

The pieces of cheese are filled into round pressing moulds (9-10 kg) andpressed with 6-8 kg/cm² at 17°-18° C. for 4 hours.

The final whole cheeses are salted in a salt bath of 24 wt. % NaCl at12°-15° C. for 3-5 days and ripened at 14°-16° C. for 2-3 months.Thereafter, either oil is rubbed into the cheese or the cheese is coatedwith wax and further ripened for 2-3 months at 5°-10° C.

EXAMPLE 7 Production of Spreadable Processed Cheese

Processed cheese with 45 wt. % fat in the dry weight, spreadable

15.0 kg Emmentaler

6.0 kg Chester

2.0 Tilsiter

2.5 kg whey powder

3.0 kg butter

2.0 kg premelt goods

0.10% Maddrell

0.90% P71 (na polyphosphate with P₂ O₅ 71%) 22.6 kg water

The above products are mixed together in a stirrer vessel and, whilestirring slowly, heated up in about 10-20 minutes to the melttemperature of 90°-92° C. by passing through of steam. Thereafter, it ishomogenised by vigorous stirring, the mass is poured into moulds, cooledto room temperature and temporarily stored for 12 hours, the finalstorage until use takes place at 6° C.

A spreadable processed cheese is obtained which contains 46 wt. % of fatin the dry material in the case of a total dry weight of 46 wt. %. Evenafter a storage time of 4-6 months, appearance and consistency do notchange.

EXAMPLE 8 Production of Processed Cheese from Fresh Cheese (70% wt. % offat in the dry material)

30.0 kg fresh cheese (according to Example 3)

0.45 kg processing salt (trisodium citrate/sodium polyphosphate--60 wt.% P₂ O₅)

0.1 kg citric acid

0.1 kg sodium polyphosphate according to Example 7

1.0 kg Na caseinate

2.0 kg butter

2.0 kg water

are heated to about 90° C. by passing through of steam for 10 min andfurther worked up according to Example 4. In spite of the smallprocessing salt content, a satisfactory processed cheese is obtainedwhich, even after storage period of 6 months, is unchanged.

In the above Examples, all statements of percentage refer to percentagesby weight insofar as nothing otherwise is stated.

EXAMPLE 9 Investigation of the ripening behaviour

Cuttable whole cheeses (Gouda type) produced according to Example 3 or 6are compared with corresponding whole cheeses which contain nostabiliser, nitrate as stabiliser or polyphosphate with a P₂ O₅ contentof below 70%.

According to Example 3, P₂ O₅ contents of 70.5, 73 and 76 were tested.

According to Example 6, 90% of Maddrell'salt was mixed with 10%polyphosphate with a P₂ O₅ content of 70.5, 73 and 76%.

Sodium nitrate was added in an amount of 10 g/ 100 1 of dairy milk.

As polyphosphate comparison, there were used polyphosphates with P₂ O₅contents of 60; 64; 68 and 70% in an amount of 0.25-1.0 g/l of dairymilk.

The ripening was observed over a period of 13 weeks. The results aregiven in the accompanying Figure, whereby, by late blowing is understoodan inflation of the wax covering and by swelling a tearing due toexcessive blowing. The curve of the product according to the inventionis designated with P, that with nitrate with N, the control with x andthat with processing phosphate with O. The various phosphate mixturesthereby give identical curves.

Results:

1. The addition of the polyphosphates P 60-P 70 show, not only in thecase of addition to dairy milk but also in the case of use in thewashwater in the case of use in natural cheese, no influence on theformation of anaerobic micro-organisms. Natural cheese which have beentreated with these polyphosphates already show after 4 weeks faultyfermentation or late blowing, as is also more strongly the case in thezero experiment (without nitrate or polyphosphate addition).

2. After a storage time of 8-12 weeks, cheese treated with nitrate alsoshow indications of a faulty fermentation which is brought about by thedevelopment of anaerobic micro-organisms.

3. All cheese which have been produced with the addition of thepolyphosphates P 70.5, P 73, P 76 and mixtures of Maddrell/P 70.5,Maddrell/P 73, Maddrell/ P 76 (ratio 90/10), as well as Maddrell,showed, even after 13 weeks storage period, no indication of a faultyfermentation or late blowing.

We claim:
 1. A method of making natural cheese or processed cheese or cheese preparations from cheese raw mass, comprising the step of adding to said cheese raw mass an acidic sodium polyphosphate, wherein said acidic sodium polyphosphate has a P₂ O₅ content within the range of from 70.5 to 77 wt %, an Na₂ O content within the range of from 20 to 27 wt %, a water content within the range of from 2 to 3 wt % and an average linear degree of condensation within the range of from 8 to
 20. 2. The method as claimed in claim 1, wherein said polyphosphates are present as comparatively long chain catena compounds which are optionally cross-linked, and wherein said polyphosphates contain less than 2 wt % of sodium metaphosphates.
 3. The method as claimed in claim 1, wherein said polyphosphates have a P₂ O₅ content of from 71 to 75 wt % and an Na₂ O content of from 22 to 26 wt %.
 4. The method as claimed in claim 1, wherein said method produces cuttable cheese, said cheese raw mass includes milk, and wherein said method comprises the addition of, per liter of milk, from 0.001 to 0.05 wt % of polyphosphate.
 5. The method as claimed in claim 4, wherein said method comprises the addition of, per liter of milk, from 0.003 to 0.01 wt % of polyphosphate.
 6. The method as claimed in claim 1, wherein said method produces processed cheese, and wherein said method comprises the addition of, to said cheese raw mass, from 2 to 4 Wt % of polyphosphate.
 7. The method as claimed in claim 6, wherein said method comprises the addition of, to said cheese raw mass, from 0.1 to 1 wt % of polyphosphates in combination with other processing salts.
 8. The method as claimed in claim 7, wherein said method comprises the addition of, to said cheese raw mass, 0.5 wt % of polyphosphates in combination with other processing salts.
 9. The method as claimed in claim 1, wherein said method produces cheese preparations from fresh cheese mass, said method being further characterized by the addition of from 0.1 to 0.5 wt % of said polyphosphate to said mass.
 10. The method as claimed in claim 1, wherein from 0.1 to 10 parts by weight of Maddrell's salt are present per 1 part by weight of said polyphosphate.
 11. The method as claimed in claim 1, wherein said method produces natural cheese, and wherein from 0.1 to 1 parts by weight of Maddrell'salt are present per 1 part by weight of said polyphosphate.
 12. The method as claimed in claim 11, wherein said method produces processed cheese, and wherein from 1 to 10 parts by weight of Maddrell's salt are present per 1 part by weight of said polyphosphate. 